Released: March 04, 2004

Blighted Tips on Junipers Symptom of Cureless Disease

MANHATTAN, Kan. – Upright and spreading junipers both can develop odd symptoms in February and March. Throughout the plant, branches’ final 2 to 6 inches start turning a dull green and then either red or yellow.

“Those are the first, most noticeable symptoms of Kabatina tip blight, caused by the fungus Kabatina juniperi. When you look closely at infected branches, you’ll also find small grey to silver wounds. And these lesions will be dotted with small black fruit-type bodies at the base of the discolored tissue,” said Ned Tisserat, plant pathologist with Kansas State University Research and Extension.

In established junipers, the fungus-caused blight rarely leads to widespread branch dieback or plant death. The affected branch tips eventually turn a dry brown. They fall from the plant in late May or June, Tisserat said.

“Nonetheless, Kabatina tip blight can really reduce the overall quality of a planting,” he said.

In contrast, the tip blight’s damage can be extensive in young nursery stock or transplants, particularly some varieties.

“If you’re shopping for new junipers this spring, you need to inspect the plants carefully and then select only healthy-looking specimens of varieties known to be resistant,” Tisserat said. “After that, you also need to space the new plantings to allow for good air circulation. That’s a basic for preventing all kinds of fungal diseases.”

No currently available fungicide can control Kabatina tip blight, he said. Besides, the actual infection period is in the fall.

The plant pathologist added, however, that juniper owners can do several thing now to reduce the disease’s severity in established plantings:

* Avoid wounding the plants, especially in fall.

* Maintain adequate fertility, but do not overfeed.

* During dry summer weather, prune out the diseased branch tips and destroy them. But, avoid excessive pruning or shearing.

“Infection often is associated with small branch-tip wounds caused by insect feeding or mechanical damage,” Tisserat warned. “If the wounding happens while the plant’s damp, so much the worse.”

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.

Story by:
Kathleen Ward
kward@oznet.ksu.edu
K-State Research& Extension News